Organic thin film transistor and method of manufacturing the same, and semiconductor device having the organic thin film transistor

ABSTRACT

There have been problems in that a dedicated apparatus is needed for a conventional method of manufacturing an organic thin film transistor and in that: a little amount of an organic semiconductor film is formed with respect to a usage amount of a material; and most of the used material is discarded. Further, apparatus maintenance such as cleaning of the inside of an apparatus cup or chamber has needed to be frequently carried out in order to remove the contamination resulting from the material that is wastefully discarded. Therefore, a great cost for materials and man-hours for maintenance of apparatus have been required. In the present invention, a uniform organic semiconductor film is formed by forming an aperture between a first substrate for forming the organic semiconductor film and a second substrate used for injection with an insulating film formed at a specific spot and by injecting an organic semiconductor film material into the aperture due to capillarity to the aperture. The insulating film formed at the specific spot enables formation of the organic semiconductor film with high controllability. Further, the insulating film can also serve as a spacer that holds the aperture, that is, an interval (gap) between the substrates.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thin film transistor having anorganic semiconductor film and a manufacturing method thereof. Inaddition, the present invention relates to a semiconductor deviceprovided with the above thin film transistor and a manufacturing methodthereof.

2. Description of the Related Art

A display device provided with thin film transistors (TFTs) has beenstudied recent years. The display device provided with TFTs can beoperated in low-power consumption and occupy small space compared withCRT, therefore it has been used for a display portion of a personalcomputer, a PDA, or the like. These TFTs have been practicallymanufactured using inorganic semiconductor materials such as amorphoussilicon, crystalline silicon, or the like. However, there is a problemthat lots of effective substrate materials can't be used since itsprocessing temperature is above 350° C. when TFTs are manufactured usinginorganic semiconductor materials.

Consequently, in addition to the inorganic materials, a thin filmtransistor having an organic semiconductor film formed by organicmaterials (hereafter referred to as an organic TFT) has been researched.Since an organic TFT can be formed at low temperature, plastic materialscan be used for the substrate. As a result, a light and flexible devicecan be obtained. Furthermore, the organic TFT has advantages of lowproduction cost for the sake of being formed on the inexpensivesubstrate materials and low voltage for driving the device.

Dipping, casting, bar coating, spin coating, spraying, ink jetting orprinting is applied for the organic semiconductor film which use apolymer type (high-molecular type) organic material. (For example,Japanese Patent Laid Open No.2000-29403, No.2000-269504). Also, vapordeposition or the like is applied for the organic semiconductor filmwhich use a low-molecular type organic material. (For example, JapanesePatent Laid Open No. 8-228035, No.10-125924). In terms of improvinguniformity in a film thickness, spin coating and vapor deposition areoften used.

However, there have been problems that any of the above manufacturingmethods requires a special apparatus, and that formed organicsemiconductor films are so little to quantity consumed materials andmost of the used materials are discarded in the end. Moreover,maintenance of apparatus such as cleaning of the inside of an apparatuscup or a chamber has needed to be continually performed in order toremove the contamination resulting from the material that is wastefullydiscarded. Therefore, a great cost for materials and man-hours formaintenance of apparatus have been required. As a result, it has notbeen desirable to apply these methods not only for the effect on theproduction cost, but also the disastrous effect on the environmentgenerated from material wastes and liquid wastes.

It is difficult to coat the films separately by spin coating, so thatpatterning is required after coating the organic films allover. It isstill difficult to perform patterning with absolute precision by thismethod. Also, there is a possibility of a thermal decomposition sincetemperature of sublimation is close to that of the thermal decompositionin some organic materials. In addition, ink jetting, printing and someother ways have not yet come into practical use.

Moreover, in the methods above, it is difficult to form a thin anduniform organic semiconductor film and to attain a TFT characteristic.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method ofmanufacturing an organic semiconductor film that does not depend on anexpensive and special apparatus and which can use a materialefficiently. Another object of the present invention is to provide amethod of manufacturing an organic TFT which is not influenced by thepyrolysis and which can simplify the manufacturing methods that need nota patterning process.

Further, another object of the present invention is to provide a methodof manufacturing an organic semiconductor film, in which a thin anduniform organic semiconductor film can be formed.

In view of the above-mentioned problems, according to the presentinvention, it is characterized in that an organic semiconductor film isformed by a method that utilizes a phenomenon in which a solution issucked into an aperture (hereinafter, simply referred to as injectionmethod). That is, according to the present invention, a solutioncontaining an organic semiconductor film material is injected into aspot (aperture) at which the organic semiconductor film is to be formed,and a solvent is then evaporated through drying, thereby the organicsemiconductor film with thinness and uniformity is formed.

Specifically, a first substrate for forming an organic semiconductorfilm and a second substrate used for helping injection are superimposedon each other; an aperture is formed between the substrates with aninsulating film formed at a specific spot; a part (including a cornerportion), typically an end (hereinafter, simply referred to as end oredge) of both the substrates is immersed in a solution containing anorganic semiconductor film material; and the organic semiconductor filmmaterial is injected into the aperture due to capillarity to form theuniform organic semiconductor film. Thus, an organic TFT is completed.

Further, it may be that: a first substrate for forming an organicsemiconductor film and a second substrate used for helping injection aresuperimposed such that ends of both the substrates are not aligned witheach other (an offset structure); an aperture is formed between both thesubstrates with an insulating film formed at a specific spot; a solutioncontaining an organic semiconductor film material is dropped onto theends of the substrates; and the solution is sucked into the aperture tocarry out injection of the organic semiconductor film material tothereby form the uniform organic semiconductor film. Of course, it maybe that: the substrates with the offset structure are immersed in thesolution containing the organic semiconductor film material; and theorganic semiconductor film material is injected into the aperture due tocapillarity. Note that superimposition of both the substrates in such amanner that ends thereof are not aligned with each other meanssuperimposition of both the substrates in such a manner that at leastsurfaces thereof on one side are shifted from each other. On the otherhand, superimposition of both the substrates in such a mariner that endsthereof are aligned with each other means superimposition of both thesubstrates in such a manner that at least surfaces thereof on one sideare aligned with each other.

The insulating film formed at the above-described specific spot enablesthe formation of an organic semiconductor film with highcontrollability. Further, as described above, the insulating film alsoserves as a spacer that holds the aperture between the substrates,namely, an interval (gap). Note that it is sufficient that manufacturingof an organic semiconductor film in the present invention is performedat an atmospheric pressure or under an anaerobic atmosphere. Note thatthe anaerobic atmosphere indicates an atmosphere in which moisture andoxygen are eliminated, and indicates, for example, an inert gasatmosphere containing nitrogen, argon, or the like. Moreover, there maybe adopted an atmosphere in which an inert gas is supplied to a reducedpressure atmosphere obtained once with the purpose of removing moistureand oxygen.

According to the present invention as described above, the semiconductorfilm with a very thin thickness (approximately several tens to 100 Å)can be formed. Further, according to the present invention, the organicsemiconductor film can be formed with efficiency, and thus, there is anexpectation for simplification of the manufacturing process.

Further, according to the present invention, the organic semiconductorfilm can be formed only at the specific spot. Thus, apparatusmaintenance and cost of cleaning solution and material can beeliminated, and therefore, total cost can be reduced. As a result, alow-cost semiconductor device provided with an organic TFT can beprovided. Further, according to the present invention, there can beprovided a method of manufacturing an organic semiconductor film, withwhich materials to be wasted and discarded are eliminated, with whichliquid wastes along with apparatus maintenance and cleaning are notproduced, and which is friendly to the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are diagrams showing a method of manufacturing anorganic thin film transistor according to the present invention;

FIGS. 2A, 2B and 2C are diagrams each showing a shape of a bank and aninjection process according to the present invention;

FIGS. 3A, 3B and 3C are diagrams each showing a shape of a bank and aninjection process according to the present invention;

FIGS. 4A, 4B and 4C are diagrams each showing a shape of a bank and aninjection process according to the present invention;

FIGS. 5A, 5B and 5C are diagrams each showing a shape of a bank and aninjection process according to the present invention;

FIGS. 6A, 6B and 6C are diagrams each showing a shape of a bank and aninjection process according to the present invention;

FIGS. 7A and 7B are diagrams showing a method of manufacturing anorganic thin film transistor according to the present invention;

FIGS. 8A, and 8B are diagrams showing a method of manufacturing anorganic thin film transistor according to the present invention;

FIGS. 9A, 9B, 9C, 9D, 9E and 9F are diagrams showing a method ofmanufacturing an organic thin film transistor according to the presentinvention;

FIG. 10 is a diagram showing an organic thin film transistor accordingto the present invention, which is used in measurement;

FIG. 11 is a chart showing results of the measurement of the organicthin film transistor according to the present invention;

FIG. 12 is a chart showing results of the measurement of the organicthin film transistor according to the present invention;

FIGS. 13A and 13B are diagrams showing a method of manufacturing anorganic thin film transistor;

FIGS. 14A and 14B are diagrams showing a method of manufacturing anorganic thin film transistor; and

FIGS. 15A and 15B are diagrams showing a method of manufacturing anorganic thin film transistor.

EMBODIMENT MODE Detailed Description of fhe Preferred Embodiment

Hereinafter, embodiment modes of the present invention will be describedwith reference to the accompanying drawings.

Embodiment Mode 1

In this embodiment mode, description will be made of a method of formingan organic semiconductor film at a predetermined portion throughinjection.

As shown in FIG. 1A, an element substrate 110 is prepared on which agate electrode 101 formed on an insulating surface thereof, a gateinsulating film 102 provided so as to cover the gate electrode (refer toa sectional view taken along the line A-A′ of FIG. 1A), a sourceelectrode and a drain electrode 103 provided so as to overlap endportions of the gate electrode through the gate insulating film, and aninsulating film (hereinafter referred to as bank) 104, which is providedon the source electrode and the drain electrode and has a desiredopening portion 105, are formed. Note that the opening portion includesa groove and a concave portion which are provided between adjacentbanks, and is not limited in terms of shape and size, and that theopening portion may be provided over pixels or provided to each pixel.Further, a substrate (hereinafter referred to as injection auxiliarysubstrate) 112 which exhibits satisfactory wettability to an organicsemiconductor material (hereinafter referred to as organic material) tobe injected and which has a flat surface is superimposed on the elementsubstrate 110 (refer to the sectional views of FIG. 1A). At this time,UV processing may be performed, a surface active agent or the like maybe used, or application of an organic or inorganic material may beperformed through spin coating or the like, with respect to theinjection auxiliary substrate 112 in order to improve wettability. Notethat a quartz substrate of which surface has been subjected to polishingprocess and which has a thickness of 1.1 mm is used as the injectionauxiliary substrate 112 in this embodiment mode.

Then, a uniform pressure is applied to the entire surface such that theinjection auxiliary substrate 112 is superimposed on the elementsubstrate 110, thereby performing fixation of both the substrates. Notethat it is preferable that the element substrate 110 and the injectionauxiliary substrate 112 are fixed to each other with an adhesive. Theinjection auxiliary substrate is superimposed on the element substrate,thereby forming an aperture 115 in which the opening portion of the bankhas a long, narrow, and linear (tubular) shape (refer to the sectionalview taken along the line B-B′ of FIG. 1A).

Next, a solution 116 of an organic material dissolved in a solvent isprepared. As the organic material, an organic molecular crystal or anorganic polymeric compound material may be used. As specific examples ofthe organic molecular crystal, polycylic aromatic compounds, conjugateddouble bond compounds, carotene, macro ring compounds, and complexesthereof, phthalocyanine, electronic transfer type complexes, andtetrathiofulvalenes: TCNQ complexes, free radicals,diphenylpicrylhydrazyl, pigments and proteins may be given. Further, asspecific examples of the organic polymeric compound material, polymerssuch as conjugated polymers, CT complexes, polyvinylpyridine, iodine andphthalocyanine metal complexes may be given. Particularly, aπ-conjugated polymer of which the skeleton is formed from conjugateddouble bond, such as polyacetylene, polyaniline, polypyrrole,polythienylene, polythiophene derivatives, poly(3-hexylthiophene) [P3HT;a polymere where the alkyl group of a polythiophene derivative with aflexible alkyl group introduced into a third position of polythiopheneis a hexyl group], poly(3-alkylthiophene), poly(3-docoslthiophene),polyparaphenylene derivatives or polyparaphenylenevinylene derivativesis preferably used.

Further, as to the solvent, there may be used one in which the organicmaterial is sufficiently dissolved and which has high wettability to theelement substrate and the injection auxiliary substrate. Examples of thesolvents include chloroform, toluene, xylene, tetrahydrofuran, carbontetrachloride, benzene, dichlorobenzene, methyl ethyl ketone, anddioxane. Further, wettability may be improved by processing the surfaceof the element substrate or injection auxiliary substrate with a UVcleaner or the like and imparting hydrophobic property or hydrophilicproperty to the surface.

Note that, in this embodiment mode, the solution 116 is prepared asfollows: poly(3-hexylthiophene), which is the organic material, isdissolved in 3.5 mg/ml of chloroform; and the resultant is passedthrough a filter with a pore size of 0.5 μm.

Subsequently, as shown in FIG. 1B, an injection portion 117 provided tothe fixed substrates is immersed in the solution 116. Then, the organicmaterial in the solution is injected into the aperture 115 betweensubstrates due to capillarity.

Thereafter, the solvent is evaporated through drying, thereby beingcapable of forming the organic semiconductor film in the opening portionof the bank (which corresponds to the aperture in the state in which theinjection auxiliary substrate is superimposed on the element substrate).Note that, since the solvent is evaporated at this time, the organicsemiconductor film is coagulated and thinned. Then, the fixed injectionauxiliary substrate is separated from the element substrate, and as aresult, there can be obtained an organic TFT in which the organicsemiconductor film with a uniform thickness is formed. Further, thesolvent may be evaporated through drying after the injection auxiliarysubstrate is separated from the element substrate.

Note that the source electrode, drain electrode, and gate electrode andrespective wirings may be connected through contact between the elementsubstrate and the TFT. Further, the wiring layer and the insulating filmmay be sequentially laminated in order to secure the layer for formingthe wiring. Note that, as the need arises, the insulating film may beformed of a resin material such as polyimide or acrylic to also attainleveling. Alternatively, after an oxide film, a nitride film, or thelike is formed of an inorganic material, leveling property may besecured by performing chemical mechanical polishing or mechanicalpolishing through CMP, ELID, or the like to the formed film.

Further, the shape of the bank having the opening portion may beappropriately designed. Hereinafter, description will be made ofexamples of bank shapes and states of injection with reference to FIGS.2A to 4C. Note that FIGS. 2A to 4C each show a top view of a state inwhich an element substrate (first substrate) and an injection auxiliarysubstrate (second substrate) are superimposed and fixed to each other.In addition, although ends of the first substrate and the secondsubstrate are aligned at an injection portion in each of FIGS. 2A to 4C,a structure in which the ends are not aligned with each other (offsetstructure) may also be adopted.

A bank 201 in FIG. 2A has a shape in which an aperture is formed only inan upper portion of a TFT, that is, a region where an organicsemiconductor film is formed. The bank having such a shape provides alarge contact area between the first substrate and the second substrateand easily attains pressure uniformity. Thus, injection of a solution202 can be performed in a stable manner.

Then, as shown in FIGS. 2B and 2C, the solution 202 is injected from aninjection portion 203. It is sufficient that the injection portion 203is provided at an end of the substrates, and injection is lessinfluenced by air and the like with the narrower injection portion.Thus, the solution can be injected uniformly. Further, the injectionportion may take the offset structure for the purpose of reducing theinfluence of air and the like, and immersion may be carried out to sucha degree that the solution 202 contacts the bank 201.

A bank 301 in FIG. 3A has a shape in which the bank is provided only ata portion necessary for injecting an organic semiconductor film into anaperture. That is, the bank 301 has a shape in which the bank 201 inFIG. 2A is provided with a space (region where a bank is not provided).The bank formed as described above is effective for preventing fromdeteriorating due to a capacitance formed in the upper portion and othermaterials

Then, as shown in FIGS. 3B and 3C, a solution 302 is injected from aninjection portion 303. Similarly to FIGS. 2A to 2C, it is preferablethat: the injection portion is made narrow in order to avoid theinfluence of air and the like; and the injection portion has the offsetstructure to carry out immersion to such a degree that the solution 302contacts the bank 301.

A bank 401 in FIG. 4A has a shape similar to that of the bank 201 inFIG. 2A, and corresponds to a case where an injection portion 403 isprovided at a corner portion of the substrates. The bank 401 and theinjection portion 403 formed as described above can reduce a contactarea between the substrates and a solution 402. Therefore, possibilityof contamination from the substrates to the solution can be reduced, andthe influence of air and the like can be eliminated. Note that FIGS. 4Band 4C each show a state in which the solution 402 is being injected.

In order to perform injection with more uniformity, an interval (gap)between the first substrate and the second substrate and an interval(width) between banks may be controlled. For example, the gap ispreferably set to several μm or less.

As described above, according to the present invention, the organicsemiconductor film can be injected into the necessary portion with theinsulating film formed at the specific spot and with the injectionportion provided to the substrates. That is, the injection method of thepresent invention enables the formation of the organic semiconductorfilm with efficiency, and thus, material costs can be reduced. Further,according to the present invention, the organic semiconductor film canbe formed at the specific spot, and thus, apparatus maintenance and costof a cleaning solution can be eliminated.

Embodiment Mode 2

In this embodiment mode, FIGS. 13A and 13B show an example of a casewhere: an offset structure is taken in which a first substrate and asecond substrate are superimposed such that ends thereof are not alignedwith each other; and a solution containing an organic material isdropped.

First, as shown in FIG. 13A, similarly to Embodiment Mode 1, a gateelectrode 1301, a gate insulating film 1302, a source electrode and adrain electrode 1303, and an insulating film 1304 that is to serve as abank are formed on an insulating substrate 1310, and an injectionauxiliary substrate 1312 is adhered to the insulating substrate 1310 toform an aperture 1305. The substrates are adhered to each other with anoffset region 1320 provided in a state in which an end of the adheredinsulating substrate (first substrate) 1310 is long shifted from an endof the injection auxiliary substrate (second substrate) 1312 (refer to asectional view taken along the line A-A′ of FIG. 13A). Note that, as tothe adherence of the injection auxiliary substrate 1312, the insulatingsubstrate 1310 and the injection auxiliary substrate 1312 may be fixedto each other, and are preferably adhered to each other with an adhesiveor the like.

Then, as shown in FIG. 13B, a solution 1321 containing an organicmaterial is dropped to the offset region 1320 to make the solutionsucked into the aperture. Plural dropping points may be provided to theoffset region 1320. Note that the solution 1321 may be synthesized bythe organic material and solvent described in Embodiment Mode 1.Thereafter, the solvent is evaporated through drying, thereby beingcapable of forming an organic semiconductor film in an opening portionof the bank (which corresponds to the aperture in the state in which thefirst substrate and the second substrate are superimposed on eachother). Note that, since the solvent is evaporated at this time, theorganic semiconductor film is coagulated and thinned. Then, the fixedinjection auxiliary substrate is separated from the element substrate,and as a result, there can be obtained an organic TFT in which theorganic semiconductor film with a uniform thickness is formed.

Further, dropping is performed to each column of organic TFTs as to thesecond substrate, and thus, injection of the solution can be performedwithout failure. Moreover, the second substrate may be provided to eachorganic TFT. However, it is necessary that the substrate is not affectedby the solution for the adjacent substrate.

As described above, the organic semiconductor film is formed by droppingthe solution, whereby the organic material can be easily injected evenin the case, as in a large-scale substrate, where the substrate isdifficult to be tilted for injection of the solution. As a result, theuniform organic semiconductor film can be formed. Further, the organicsemiconductor film can be formed with efficiency, and thus, materialcosts can be reduced.

Embodiment Mode 3

In this embodiment mode, a description will be made of a case where:when an organic semiconductor material or the like has anaerobicproperty, manufacturing steps of a TFT, particularly, an injection stepof an organic material for forming an organic semiconductor film isperformed in an anaerobic atmosphere; and sealing is performed while theabove state is maintained to attain hermetic sealing, with reference toFIGS. 5A to 5C.

An element substrate (first substrate) is formed similarly to EmbodimentMode 1. Then, as shown in FIG. 5A, a seal member 502 is formed on thesubstrate, and a first substrate and a second substrate are fixed toeach other so as to have at least two opening regions 501 a and 501 bwhere the seal member does not exist. Then, the first substrate and thesecond substrate are superimposed and hermetically adhered to each otherthrough application of a uniform pressure to the entire surface bysealing member 502 while which is hardened. Note that the seal member502 may be formed of a thermosetting epoxy resin or a UV cured resin,and a material with low permeability against moisture and oxygen isdesirably used for the seal member 502. Further, when being formed of athermosetting material, the seal member is hardened by using an oven, ahot plate, or the like. When being formed of UV cured material, the sealmember is irradiated with UV light, and is further hardened throughburning with the use of the oven or the hot plate if necessary.

Thus, a portion between the second substrate and a bank 503, that is, aportion (region) where the organic semiconductor film is to be formedhas a long, narrow, and linear (tubular) shape, whereby an aperture 504is formed. Then, the substrates in this state are transferred to underan anaerobic atmosphere such as an inert gas (for example, nitrogen gas)atmosphere. With one of the opening regions 501 a and 501 b of theadhered substrates serving as an injection portion for the organicmaterial, injection of a solution 505 is performed from, for example,the injection portion 501 b. Then, as shown in FIG. 5B, the organicmaterial is injected into the long and narrow aperture 504 due tocapillarity.

Further, in the case of suppressing influence of moisture, oxygen, andthe like as much as possible, the adhered substrates are transferred tothe inside of an apparatus capable of realizing high vacuum, forexample, a chamber having a cryo pump. In the chamber, while high vacuumis realized and a predetermined pressure value is maintained, nitrogenwith high impurity is circulated and leaked. Thereafter, when thepressure reaches an atmospheric pressure, the solution 505 may besupplied to the inside of the chamber and injected from the injectionportion. Further, as described in Embodiment Mode 2, the solution may bedropped with the offset structure.

Thereafter, the solvent is evaporated to be dried through naturalseasoning, baking, or the like in a state where the first substrate andthe second substrate are adhered to each other. As a result, the organicsemiconductor film is formed in the aperture 504 between the banks.

Finally, as shown in FIG. 5C, a sealing material 506 formed of a UVresin is attached to each of the opening regions 501 a and 501 b, and ishardened by being irradiated with UV light, thereby completing anorganic TFT sandwiched by the first substrate and the second substrate.Further, the opening regions 501 a and 501 b are sealed in the inert gasatmosphere kept after drying, whereby an organic TFT can be formed evenby using the organic material susceptible to moisture and oxygen.Moreover, it is desirable that the steps of: the formation of the bankon the first substrate; injection of the injection material; and sealingare performed in the same chamber. In addition, a space in which asheet-like drying agent can be arranged may be provided between thefirst substrate and the second substrate.

The organic TFT formed as described above enables reduction of moistureand oxygen in the element to the utmost. Accordingly, longer-termreliability can be secured.

Further, the injection method of the present invention enables theformation of an organic semiconductor film with efficiency, and thus,material costs can be reduced. Furthermore, according to the presentinvention, an organic semiconductor film can be formed at the specificspot, and thus, apparatus maintenance and cost of a cleaning solutioncan be eliminated.

Embodiment Mode 4

In this embodiment mode, description will be made of an example of acase where a formation range of an organic semiconductor film is widebecause of a large-scale substrate although, in the case of a substratewith a size at a certain degree, it is sufficient that an organic TFT isformed after an area of a bank is somewhat increased, with reference toFIGS. 6A to 6C.

As shown in FIG. 6A, a columnar spacer 603 is formed inside a sealmember, in particular, inside a bank 602 through the same step as thatfor forming the bank. By forming the columnar spacer 603 as describedabove, an interval (gap) between a first substrate and a secondsubstrate each of which has a large size can be kept uniform, and theorganic semiconductor film can be formed over a wide range.

As shown in FIG. 6B, a solution 604 is prepared, and the substrates,which have been adhered so as to keep the interval (gap) uniform, areimmersed in the solution 604. Then, an organic material is injected intoan aperture due to capillarity. Note that FIGS. 6B and 6C each shows astate in which the solution 604 is being injected. Even in the case ofthe large-scale substrate and the wide formation range of the organicsemiconductor film, the solution 604 can be injected with efficiency.

Further, in this embodiment mode, the arrangement of the columnar spaceris appropriately set. As a result, the formation point of the organicsemiconductor film can be controlled, and also, the organicsemiconductor film can be formed at random. Further, in this embodimentmode, the solution may be dropped by using the offset structure shown inEmbodiment Mode 2.

The above-described injection method of the present invention enablesthe formation of the organic semiconductor film with efficiency alsowith respect to the large-scale substrate. As a result, material costscan be reduced.

Embodiment Mode 5

In this embodiment mode, description will be made of an example ofmanufacturing of an organic TFT with reference to FIGS. 7A and 7B. Notethat FIG. 7A is a top view, and FIG. 7B is a sectional view taken alongthe line A-A′ of FIG. 7A.

First, a substrate 701 having an insulating surface (hereinafterreferred to as insulating substrate) is prepared. Note that it issufficient that: the insulating substrate 701 is a substrate with heatresistance that can withstand a processing temperature; and a glasssubstrate, a plastic substrate, or a quartz substrate is used. Then, afirst conductive film with a thickness of 100 to 200 nm is formed on theinsulating substrate 701 by sputtering. Further, the first conductivefilm may be formed of a metal material that can function as a gateelectrode, and may be specifically formed of an element selected fromthe group consisting of Ta, W, Ti, Mo, Al, and Cu or an alloy materialor compound material containing the element as its main constituent.Thereafter, a resist is applied onto the first conductive film, bakingis performed thereto, and exposure is performed thereto using apatterning mask to carry out developing. Then, the first conductive filmis subjected to etching through dry etching. After etching, the resistis peeled off using a peeling solution, thereby forming a gate electrode702. Note that the gate electrode 702 is formed using W in thisembodiment mode.

Further, the gate electrode may be held in common by plural TFTs. Thestructure is effective for a pixel TFT in an active matrix circuit.

Further, although not shown in the figure, an insulating film may beprovided between the insulating substrate 701 and the gate electrode702. The insulating film serves as a barrier layer against water vaporor organic gas which enters from an external environment, and canprevent an organic semiconductor material or the like from deterioratingdue to the water vapor or organic gas.

After the gate electrode 702 is formed, a first insulating film 703 isformed with a thickness of 100 to 200 nm. Note that the first insulatingfilm 703 is formed of an insulating film containing silicon oxide,silicon oxynitride, or other silicon by using plasma CVD or sputtering.In this embodiment mode, the first insulating film 703 is formed of asilicon oxynitride film by using plasma CVD. Of course, the firstinsulating film 703 is not limited to the silicon oxynitride film, andthe other insulating film containing silicon may be used in a form of asingle layer or lamination layer structure. The first insulating film703 formed as described above functions as a gate insulating film.

Next, a second conductive film with a thickness of 200 nm is formed onthe gate insulating film 703 by sputtering. The second conductive filmformed here needs to be connected with an organic semiconductor filmthrough an ohmic contact. Therefore, in the case of a p-type organicsemiconductor material, the second conductive film needs to be formed byusing a conductive film material (metal material) having a work functionlarger than an ionization potential of the organic semiconductormaterial. On the contrary, in the case of an n-type organicsemiconductor material, the second conductive film needs to be formed byusing a conducive film material (metal material) having a work functionsmaller than an ionization potential of the organic semiconductormaterial. In this embodiment mode, p-type poly(3-hexylthiophene)[ionization potential=4.64] is used as the organic semiconductormaterial. Thus, the second conductive film is formed using W [workfunction=4.75] having a work function larger than the ionizationpotential.

Thereafter, a resist is applied onto the second conductive film, bakingis performed thereto, and exposure is performed thereto with the use ofa wiring patterning mask to carry out developing. Then, etching of thesecond conductive film is performed through dry etching. After etching,the resist is peeled off using a peeling solution, whereby a pair ofsecond conductive films, that is, a source electrode 704 a and a drainelectrode 704 b are formed.

Subsequently, application of a resist is further performed, baking isperformed thereto, and exposure is performed thereto with the use of acontact mask to carry out developing. Then, etching of the gateinsulating film 703 is performed through wet etching. After etching, theresist is peeled off using the peeling solution. Through the step, asurface of the gate electrode 702 is exposed. Thus, application of avoltage to the gate electrode is enabled.

Then, application of photosensitive acrylic is performed, and exposureis performed thereto with the use of a mask for forming a bank to carryout developing. Then, baking is performed to form a bank 705 having anopening portion on the gate electrode. The opening portion is formed tohave a hem with a tapered angle of 45 to 60 degrees, and is formed suchthat an end surface thereof has a curved surface with a first radius ofcurvature at its upper end portion and a curved surface with a secondradius of curvature at its lower end portion. Note that materials forthe bank may be organic materials such as polyimide, polyamide,polyimideamide and BCB (benzocyclobutene) or inorganic materials, whichinclude silicon, such as silicon oxide, silicon nitride, siliconoxynitride and a lamination film of the above substances. Further, it ispreferable that the opening portion is formed through dry etching in thecase of using the inorganic material.

Thereafter, injection of a solution is performed by any of the injectionmethods described in Embodiment Modes 1 to 4, thereby forming an organicsemiconductor film 706.

Note that the source electrode, drain electrode, and gate electrode andrespective wirings may be connected through contact between the elementsubstrate and the TFT. That is, the gate electrode is connected to ascanning line through contact for taking the gate electrode out.Further, the wiring layer and the insulating film may be sequentiallylaminated in order to secure the layer for forming the wiring.

The organic TFT thus formed enables the formation of the organicsemiconductor film with efficiency, and thus, material costs can bereduced. Further, according to the present invention, the organicsemiconductor film can be formed at the specific spot, and thus,apparatus maintenance and cost of a cleaning solution can be eliminated.

Embodiment Mode 6

In this embodiment mode, description will be made of an example ofmanufacturing of an organic TFT in which, after the formation of a bank,a source electrode and a drain electrode are formed, differently fromEmbodiment Mode 5, with reference to FIGS. 8A and 8B.

First, a gate electrode 802 is formed on an insulating substrate 801 asin Embodiment Mode 4. At this time, the gate electrode may be held incommon by plural TFTs. Further, although not shown in the figure, aninsulating film may be provided between the insulating substrate 801 andthe gate electrode 802. The insulating firm serves as a barrier layeragainst water vapor or organic gas which enters from an externalenvironment, and can prevent an organic semiconductor material or thelike from deteriorating due to the water vapor or organic gas.

Next, a gate insulating film 803 is formed on the gate electrode 802.Then, a photosensitive acrylic material is applied onto the gateinsulating film 803, baking is performed thereto, and exposure isperformed thereto with the use of a mask for forming a bank to carry outdeveloping. Thereafter, cleaning with flowing water and baking aresequentially performed thereto to form a bank 804 having an openingportion. Note that materials for the bank may include organic materialssuch as polyimide, polyamide, polyimideamide, and BCB (benzocyclobutene)and inorganic materials, which include silicon, such as silicon oxide,silicon nitride, silicon oxynitride, and a lamination film of the abovesubstances. Further, it is preferable that the opening portion be formedthrough dry etching in the case of using the inorganic material.

Next, a second conductive film with a thickness of 200 nm is formed onthe bank 804 by sputtering. The second conductive film formed here needsto be connected with an organic semiconductor film through an ohmiccontact. Therefore, in the case of a p-type organic semiconductormaterial, the second conductive film needs to be formed by using aconductive film material (metal material) having a work function largerthan an ionization potential of the organic semiconductor material. Onthe contrary, in the case of an n-type organic semiconductor material,the second conductive film needs to be formed by using a conducive filmmaterial (metal material) having a work function smaller than anionization potential of the organic semiconductor material. In thisembodiment mode, p-type poly(3-hexylthiophene) is used as the organicsemiconductor material. Thus, the second conductive film is formed usingITO having a large work function.

Thereafter, a resist is applied onto the ITO, baking is performedthereto, and exposure is performed thereto with the use of a wiringpatterning mask to carry out developing. Then, cleaning with flowingwater is performed thereto, and etching of the ITO is performed throughwet etching. After etching, the resist is peeled off using a peelingsolution, whereby a source electrode 805 a and a drain electrode 805 bare formed.

Subsequently, application of a resist is further performed, baking isperformed thereto, and exposure is performed thereto with the use of acontact mask to carry out developing. Then, etching of the gateinsulating film 803 is performed through wet etching. After etching, theresist is peeled off using the peeling solution. Through the step, asurface of the gate electrode 802 is exposed. Thus, application of avoltage to the gate electrode is enabled.

Thereafter, injection of a solution is performed by any of the injectionmethods described in Embodiment Modes 1 to 4, thereby forming an organicsemiconductor film 806.

Note that, as described with reference to FIGS. 14A and 14B, a sourceelectrode, a drain electrode, and a gate electrode and respectivewirings may be connected through contact between the element substrateand the TFT, thereby forming a semiconductor element. Further, a bankand a source or a drain electrode are in inverse top-and-bottom relationto each other in comparison between the structures in FIGS. 14A and 14Band the structures in FIGS. 8A and 8B. Thus, a contact area between adrain electrode and an electrode (pixel electrode, anode, or cathode)can be widely secured.

Thereafter, a liquid crystal material or a light emitting layer may beappropriately provided, thereby completing a liquid crystal displaydevice (liquid crystal display module) or an EL display device (ELdisplay module).

In the organic TFT formed as described above, the organic semiconductorfilm can be formed with efficiency, and thus, material costs can bereduced. Further, according to the present invention, the organicsemiconductor film can be formed at the specific spot, and thus,apparatus maintenance and cost of a cleaning solution can be eliminated.

Further, in the structure of this embodiment mode, the contact areabetween the source electrode and the drain electrode and the organicsemiconductor film is wide, which leads to reduction of contact failure.Moreover, the source electrode and the drain electrode are providedwhile covering the bank, and thus, a large margin of the region wherethe bank is formed can be secured.

Embodiment Mode 7

This embodiment mode describes a method of manufacturing the organic TFTthat is formed using organic materials with reference to FIG. 9.

As illustrated in FIG. 9A, a substrate 901 having an insulating surfaceis prepared. This substrate may be any substrate as long as it isflexible and it is light-transmissive, such as polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone(PES), polycarbonate (PC), polyether imide. In this embodiment mode,plastic substrate is used. The thickness of the substrate 901 ispractically 10 to 200 μm.

Then a barrier layer 902 is formed on a substrate 901. It is desiredthat the barrier layer 902 is made of AlO_((x))N_((1-x)) (where x=0.01to 20 atomic %), a silicon nitride without containing hydrogen formed byRF sputtering or other insulating materials. The insulating materialserves as a barrier layer against the water vapor or organic gas thatenters from an external environment and can prevent the organicsemiconductor material and the like from deteriorating by the watervapor or organic gas.

A first conductive film which functions as a gate electrode 903 of theTFT is formed on the barrier layer 902 by using a conductive paste, or aPEDOT(polythiophene). As the conductive paste, a conductive carbonpaste, a conductive silver paste, a conductive copper paste, aconductive nickel paste, or the like is used. The first conductive filmis formed into a predetermined pattern by screen-printing, roll-coating,or ink jetting. The first conductive layer is formed into apredetermined pattern using the conductive paste, and, subjected toleveling, then, drying and curing at 100 to 200° C.

As shown in FIG. 9B, a first insulating film which functions as a gateinsulating film 904 is formed on the gate electrode 903. The firstinsulating film is formed using an acrylic resin, a polyimide resin, apolyamide resin, a phenoxy resin, a nonaromatic polyfunctionalisocyanate, or a melamine resin by roll-coating, spraying, ink jetting,spin coating and screen printing. Considering the gate voltage, it ispreferable that the film thickness of the gate insulating film is about100 to 200 nm.

Then, as illustrated in FIG. 9C, the second conductive film thatfunctions as a source electrode 905 a or a drain electrode 905 b isformed on the gate insulating film 904. As a material for the secondconductive film, it is desired to use a metal having a large workfunction for being an ohmic contact with the semiconductor layers, sincemany organic semiconductor materials for transporting the electriccharge are p-type semiconductors that transport positive holes ascarriers. Concretely, the second conductive film is formed using aconductive paste including a metal such as gold, platinum, chrome,palladium, aluminum, indium, molybdenum or nickel, or an alloy thereofby printing or roll coating.

Subsequently, as shown in FIG. 9D, the second insulating film providedas a bank 906 is formed on the source electrode 905 a or the drainelectrode 905 b. Still, the second insulating film is formed usingacrylic resin, polyimide resin, polyamide resin, phenoxy resin,nonaromatic polyfunctional isocyanate, and melamine resin byroll-coating, spraying, ink jetting, spin coating, and screen printingfor forming an opening portion on the top of the gate electrode to fillthe organic semiconductor film therein. In this embodiment mode, asource electrode or a drain electrode can be formed after forming a bankas described in Embodiment mode 5.

According to any injection method explained in Embodiment Mode 1 to 4, asolution is injected. In case the substrate is large or the firstsubstrate and the second substrate are flexible, it is preferable thatorganic materials are injected by dropping the solution as described inEmbodiment Mode 2. Then as shown in FIG. 9E, the solution is evaporatedthrough natural seasoning or baking to form an organic semiconductorfilm 907.

A passivation film 908 is formed as shown in FIG. 9F. The passivationfilm is formed by an insulating film including silicon such as siliconnitride film or silicon oxynitride film.

Next, as explained in FIG. 14, the source electrode, the drain electrodeor the gate electrode and each wiring take contact with and connect tothe element substrate and the TFT to form a semiconductor device.Furthermore a liquid crystal material and a light emitting layer areproperly formed to make the liquid crystal device (liquid displaymodule) or EL display device (EL display module) completed. Farther,when an insulating film including nitrogen is formed on the first andthe second insulating film according to the present invention, theinsulating film can prevent an organic semiconductor material or thelike from deteriorating due to the water vapor or organic gas.

According to the organic TFT that is formed all of the elements withorganic compound materials, light and flexible semiconductor device(specifically, liquid display device, EL display device or other displaydevice) can be obtained. Also, the cost of a semiconductor device can bereduced due to inexpensive materials and a few wasted materials.

An organic TFT according to this embodiment mode can be adapted to thesystem on panel integrating a pixel portion that displays information ina panel in visual, a communication facility that receives and sendsinformation and a computer function that records or process information.

Embodiment Mode 8

In this embodiment mode, description will be made of an example in whichan organic TFT is used as a TFT in a pixel portion of a semiconductordevice with reference to FIGS. 14A and 14B and FIGS. 15A and 15B.

As shown in FIG. 14A, and FIG. 14B which is a sectional view taken alongthe line A-A′ of FIG. 14A, a wiring (signal line) 1411 is formed on anelement substrate 1401, and an insulating film 1416 is formed so as tocover the wiring 1411. Then, a gate wiring (scanning line) 1412 isformed so as to intersect the wiring 1411 on the insulating film 1416,and an insulating film 1417 is formed so as to cover the gate wiring. Atthis time, the insulating films 1416 and 1417 may be formed of a resinmaterial such as polyimide or acrylic to also attain leveling.Alternatively, after an oxide film, a nitride film, or the like isformed of an inorganic material, leveling property may be secured byperforming chemical mechanical polishing or mechanical polishing throughCMP, ELID, or the like to the formed film.

Next, a gate electrode 1402 is connected to the gate wiring 1412 througha first contact. Thereafter, for example, as shown in FIGS. 7A and 7B, agate insulating film 1403 is formed, and a source electrode 1405 a and adrain electrode 1405 b are formed. Then, the source electrode 1405 a andthe wiring (signal line) 1411 are connected to each other through asecond contact.

Subsequently, a bank 1404 is formed on the source electrode 1405 a andthe drain electrode 1405 b, and an organic material is injected into anaperture of the bank as described in any of Embodiment Modes 1 to 4.After the injection, a solvent is evaporated through drying, whereby anorganic semiconductor film 1406 is formed.

Thereafter, an electrode 1413 (corresponding to a pixel electrode in thecase of a liquid crystal display device and to an anode (or cathode) inthe case of an EL display device) is formed so as to be connected withthe drain electrode 1405 b, as a result of which a semiconductor elementis formed. Then, a liquid crystal material or a light emitting layer isappropriately provided; further, an FPC is connected thereto through ananisotropic conductive film; and an external terminal is connectedthereto, thereby completing the liquid crystal display device (liquidcrystal display module) or the EL display device (EL display module).

Next, description will be made of a pixel portion having a structure,which is different from that in FIGS. 14A and 14B, with reference toFIGS. 15A and 15B.

As shown in FIG. 15A, and FIG. 15B which is a sectional view taken alongthe line A-A′ of FIG. 15A, a wiring (signal line) 1511 is formed on anelement substrate 1501, and an insulating film 1516 is formed so as tocover the wiring 1511. Then, a conductive film, which is to serve as agate electrode 1502, is formed so as to intersect the wiring 1511 on theinsulating film 1516. At this time, the insulating film 1516 may beformed of a resin material such as polyimide or acrylic to also attainleveling. Alternatively, after an oxide film, a nitride film, or thelike is formed of an inorganic material, leveling property may besecured by performing chemical mechanical polishing or mechanicalpolishing through CMP, ELID, or the like to the formed film.

Next, for example, as shown in FIGS. 8A and 8B, a gate insulating film1503 is formed, and a bank 1504 provided with an opening portion (whichcorresponds to an aperture in a state in which a second substrate issuperimposed on the element substrate) is formed above the gateelectrode 1502. Then, a source electrode 1505 a and a drain electrode1505 b are formed so as to cover the bank 1504. Then, the sourceelectrode 1505 a is connected to the wiring (signal line) 1511 throughcontact. Thereafter, an organic material is injected into the apertureof the bank 1504 as shown in any of Embodiment Modes 1 to 4. After theinjection, a solvent is evaporated through drying, whereby an organicsemiconductor film 1506 is formed.

Thereafter, an electrode 1513 (corresponding to a pixel electrode in thecase of a liquid crystal display device and to an anode,(or cathode) inthe case of an EL display device) is formed so as to be connected withthe drain electrode 1505 b, as a result of which a semiconductor elementis formed. Then, a liquid crystal material or a light emitting layer isappropriately provided; further, an FPC is connected thereto through ananisotropic conductive film; and an external terminal is connectedthereto, thereby completing the liquid crystal display device (liquidcrystal display module) or the EL display device (EL display module).

The structures in FIGS. 15A and 15B do not require a gate wiring. Thus,contact formation for connecting the gate wiring to the gate electrodeis not required, and the number of masks can be reduced. Further, inthis embodiment mode, the gate electrode can be held in common in eachcolumn direction. Therefore, the organic TFT is preferably used in thepixel portion.

Note that the organic TFTs shown in FIGS. 14A and 14B and FIGS. 15A and15B may be formed by using any of the methods in Embodiment Modes 5 to7. In particular, the organic TFT is formed by using the method inEmbodiment Mode 7, whereby the liquid crystal display device or ELdisplay device, which is light in weight and has high flexibility, canbe formed. Further, although the organic TFT of the present invention isused in the pixel portion in FIGS. 14A and 14B and FIGS. 15A and 15B,the organic TFT excellent in TFT characteristics may also be used in adriver circuit portion.

As to the semiconductor device (liquid crystal display device or ELdisplay device) formed as described above, the organic semiconductorfilm can be formed with efficiency, and thus, material costs can bereduced. Further, according to the present invention, the organicsemiconductor film can be formed at the specific spot, and thus,apparatus maintenance and cost of a cleaning solution can be eliminated.

Embodiments Embodiment 1

In this embodiment, Vd-Id characteristics and VG-Id characteristics weremeasured with the use of the organic TFT of the present invention. Notethat, as shown in FIG. 10, the organic TFT as a measurement sample has astructure in which, in an atmosphere: a gate electrode 1003 formed oftungsten is provided on a quartz substrate; a gate insulating film isprovided on the gate electrode; a source electrode 1001 and a drainelectrode 1002 which are formed of tungsten are provided on the gateinsulating film so as to intersect each other in a comb form; and anorganic semiconductor film is provided between the source electrode andthe drain electrode. Then, the source electrode 1001, the drainelectrode 1002, and the gate electrode 1003 are respectively providedwith measurement pads (source electrode pad 1011, drain electrode pad1012, and gate electrode pad 1013) for application of a measurementvoltage and detection of a current.

Further, a channel length of the organic TFT corresponds to the entireamount of an interval between the source electrode and the drainelectrode (which is indicated by L in FIG. 10), and L=3 μm isestablished. On the other hand, a channel width corresponds to theentire amount of the length of a region where the source electrodeoverlaps the drain electrode (which is indicated by W in FIG. 10), andW=7840 mm is given because the interval between the source electrode andthe drain electrode is set to 3 μm.

FIG. 11 shows measurement results in an atmosphere as to Vd-Idcharacteristics in the case where each of voltages of VG=−3, −6, −9,−12, −15, −18, and −21 V is applied to the organic TFT shown in FIG. 10.Further, FIG. 12 shows results concerning V-I characteristics inmeasurement in an atmosphere of a current of each of the sourceelectrode, the drain electrode, and the gate electrode and the gatevoltage under application of a voltage Vd=−5 V. Moreover, from theresults in FIGS. 11 and 12, there are obtained mobility of 3×10⁻⁶ cm²/Vs and an on-off ratio of 14.

The TFT characteristics depend on a thickness of a semiconductor film ora W/L ratio of a channel formation region. However, the semiconductorfilm can be formed with a thin film thickness according to the presentinvention. Therefore, the above-described TFT characteristics (mobilityand on-off ratio) can be obtained.

By implementing the present invention, thin film thickness of asemiconductor film can be obtained. Sine the organic semiconductor filmcan be made with efficiency, the material cost can be reduced.

Further, according to the present invention, the organic semiconductorfilm can be formed only at the specific spot. Thus, apparatusmaintenance and costs of cleaning solution and material can beeliminated, and therefore, total cost can be reduced. As a result, alow-cost semiconductor device provided with an organic TFT can beprovided. Further, according to the present invention, there can beprovided a method of manufacturing an organic semiconductor film, withwhich materials to be wasted and discarded are eliminated, with whichliquid wastes along with apparatus maintenance and cleaning are notproduced, and which is friendly to the environment.

1. A semiconductor device comprising: a plurality of organic thin filmtransistors provided over an insulating substrate, the organic thin filmtransistors each comprising: a first conductive film; a first insulatingfilm provided over the first conductive film; a pair of secondconductive films provided over the first insulating film; a secondinsulating film having an opening portion, and provided over the pair ofsecond conductive films; and an organic semiconductor film provided inthe opening portion, and provided over the pair of second conductivefilms, wherein the first conductive film is provided to be held incommon by the plurality of organic thin film transistors, wherein theopening portion overlaps the first conductive film, and wherein theorganic semiconductor film is in contact with the second insulating filmin the opening portion.
 2. A semiconductor device according to claim 1,wherein the first conductive film is provided so as to be in parallelwith a signal line.
 3. A semiconductor device according to claim 1,wherein the first conductive film is provided so as to intersect asignal line.
 4. A semiconductor device comprising: a plurality oforganic thin film transistors provided over an insulating substrate, theorganic thin film transistors each comprising: a first conductive film;a first insulating film provided over the first conductive film; a pairof second conductive films provided over the first insulating film; asecond insulating film having an opening portion, and provided over thepair of second conductive films; and an organic semiconductor filmprovided in the opening portion, and provided over the pair of secondconductive films, wherein the opening portion overlaps the firstconductive film, and wherein the organic semiconductor film is incontact with the second insulating film in the opening portion.
 5. Asemiconductor device according to claim 1, wherein the insulatingsubstrate is a glass substrate, a plastic substrate, or a quartzsubstrate.
 6. A semiconductor device according to claim 4, wherein theinsulating substrate is a glass substrate, a plastic substrate, or aquartz substrate.
 7. A semiconductor device according to claim 1,wherein the first conductive film comprises a material selected from thegroup consisting of Ta, W, Ti, Mo, Al, and Cu or an alloy material orcompound material containing the element as its main constituent.
 8. Asemiconductor device according to claim 4, wherein the first conductivefilm comprises a material selected from the group consisting of Ta, W,Ti, Mo, Al, and Cu or an alloy material or compound material containingthe element as its main constituent.
 9. A semiconductor device accordingto claim 1, wherein the first insulating film comprises a materialselected from the group consisting of silicon oxide, silicon oxynitride,and other silicon.
 10. A semiconductor device according to claim 4,wherein the first insulating film comprises a material selected from thegroup consisting of silicon oxide, silicon oxynitride, and othersilicon.
 11. A semiconductor device according to claim 1, wherein thesecond insulating film comprises a material selected from the groupconsisting of polyimide, polyamide, polyimide amide and BIB(benzocyclobutene) or inorganic materials, which include silicon, suchas silicon oxide, silicon nitride, silicon oxynitride and a laminationfilm of the above substances.
 12. A semiconductor device according toclaim 4, wherein the second insulating film comprises a materialselected from the group consisting of polyimide, polyamide, polyimideamide and BIB (benzocyclobutene) or inorganic materials, which includesilicon, such as silicon oxide, silicon nitride, silicon oxynitride anda lamination film of the above substances.
 13. A semiconductor deviceaccording to claim 1, wherein the organic semiconductor film comprises amaterial selected from the group consisting of polycyclic aromaticcompounds, conjugated double bond compounds, carotene, macro ringcompounds, and complexes thereof, phthalocyanine, electronic transfertype complexes, and tetrathiofulvalenes: TCNQ complexes, free radicals,diphenylpicrylhydrazyl, pigments, proteins, π-conjugated polymers, CTcomplexes, polyvinylpyridine, iodine and phthalocyanine metal complexes,polyacetylene, polyaniline, polypyrrole, polythienylene, polythiophenederivatives, poly(3-hexylthiophene) [P3HT; a polymer where the alkylgroup of a polythiophene derivative with a flexible alkyl groupintroduced into a third position of polythiophene is a hexyl group],poly(3-alkylthiophene), poly(3-docoslthiophene), polyparaphenylenederivatives or polyparaphenylenevinylene derivatives.
 14. Asemiconductor device according to claim 4, wherein the organicsemiconductor film comprises a material selected from the groupconsisting of polycyclic aromatic compounds, conjugated double bondcompounds, carotene, macro ring compounds, and complexes thereof,phthalocyanine, electronic transfer type complexes, andtetrathiofulvalenes: TCNQ complexes, free radicals,diphenylpicrylhydrazyl, pigments, proteins, π-conjugated polymers, CTcomplexes, polyvinylpyridine, iodine and phthalocyanine metal complexes,polyacetylene, polyaniline, polypyrrole, polythienylene, polythiophenederivatives, poly(3-hexylthiophene) [P3HT; a polymer where the alkylgroup of a polythiophene derivative with a flexible alkyl groupintroduced into a third position of polythiophene is a hexyl group],poly(3-alkylthiophene), poly(3-docoslthiophene), polyparaphenylenederivatives or polyparaphenylenevinylene derivatives.